Evolution of postural diversity in primates as reflected by the size and shape of the medial tibial facet of the talus
Bibliographic Data
OBJECTIVES: Comprehensive quantification of the shape and proportions of the medial tibial facet (MTF) of the talus (=astragalus) has been lacking for Primates and their closest relatives. In this study, aspects of MTF form were quantified and employed to test hypotheses about their functional and phylogenetic significance. The following hypotheses influence perceptions of primate evolutionary history but are due for more rigorous assessment: 1) A relatively large MTF distinguishes "prosimians" (strepsirrhines and tarsiers) from anthropoids and non-primate euarchontans; 2) the distinctive form of the "prosimian" MTF is a correlate of locomotor tendencies that emphasize use of vertical and small diameter supports in conjunction with inverted, abducted foot postures; and 3) the "prosimian" MTF form arose along the primate stem lineage and was present in the euprimate common ancestor. METHODS: Three-dimensional (3D) scanning was used to create scale digital models of tali (n = 378 specimens, 122 species) from which three types of variables capturing aspects of MTF form were computed: 1) MTF area relative to body mass and ectal facet area; 2) MTF shape (elliptical vs. non-elliptical); and 3) MTF dorsal restriction on the talar body (i.e., extensive vs. minimal exposure of non-articular area). Data were analyzed using both phylogenetic and traditional comparative methods including Phylogenetic Generalized Least Squares, Ordinary Least Squares, ANCOVA, ANOVA, and Bayesian Ancestral State Reconstruction (ASR). RESULTS: Extant "prosimians" are generally distinct from anthropoids and non-primate euarchontans in our quantitative representations of MTF form. MTF area (but not shape or dorsal restriction) correlates with fibular facet angle (FFa) of the talus, which has also been argued to reflect habitual pedal inversion. Among strepsirrhines, taxa that engage in grasp-leaping more frequently/effectively appear to have a relatively larger MTF than less acrobatic taxa. Directional models of evolutionary change better describe the phylogenetic distribution of MTF variation than do other models. ASR shows 1) little change in the MTF along the primate stem, 2) independent evolution of relatively large and dorsoplantarly deep MTFs in basal haplorhines and strepsirrhines, and 3) re-evolution of morphologies similar to non-euprimates in anthropoids. CONCLUSIONS: Results support the hypothesis that differences in MTF form between anthropoids and "prosimians" reflect greater use of inverted foot postures and grasp-leaping in the latter group. Although fossil "prosimians" do not have the extreme MTF dimensions that characterize many extant acrobatic leapers, these variables by themselves provide little additional behavioral resolution at the level of individual fossils due to strong phylogenetic signal. ASR suggests that some specialization for use of inverted foot postures (as required in a fine-branch niche) and modifications for grasp-leaping evolved independently in basal strepsirrhine and haplorhine lineages
Biology · Evolutionary biology · Facet (psychology) · Lemur · Phylogenetic tree · Primate · Prosimian · Anatomy · Morphological variations and asymmetry · Paleontology · Pleistocene-Era Hominins and Archaeology · Primate Behavior and Ecology · Psychology
New Cranial and Postcranial Remains of the Once Enigmatic Early Eocene Mammal Wyolestes (Mammalia, Ferae, Hyaenodonta) from North America, and Phylogenetic Evidence for its Interordinal Relationships
Gorilla calcaneal morphological variation and ecological divergence
Quantification of the position and depth of the flexor hallucis longus groove in euarchontans, with implications for the evolution of primate positional behavior
Footloose
Predicting euarchontan body mass
New fossils, systematics, and biogeography of the oldest known crown primate Teilhardina from the earliest Eocene of Asia, Europe, and North America
First navicular remains of a European adapiform (Anchomomys frontanyensis) from the Middle Eocene of the Eastern Pyrenees (Catalonia, Spain)
Locomotion, postures, substrate use, and foot grasping in the marsupial feathertail glider Acrobates pygmaeus (Diprotodontia)
Early euprimates already had a diverse locomotor repertoire
My branch is your branch
Postcrania of the most primitive euprimate and implications for primate origins
New endemic platyrrhine humerus from Haiti and the evolution of the Greater Antillean platyrrhines
Reconstruction of the locomotor repertoire of early primates in the light of astragalar and calcaneal shape
The evolution of the platyrrhine talus
First virtual endocasts of adapiform primates
Internal carotid arterial canal size and scaling in Euarchonta
New euprimate postcrania from the early Eocene of Gujarat, India, and the strepsirrhine-haplorhine divergence
Postcranial adaptation and evolution in lorisidae
Grasping Primate Origins
Size and Adaptation in Primates
Macroevolutionary Dynamics and Historical Biogeography of Primate Diversification Inferred from a Species Supermatrix
The oldest known primate skeleton and early haplorhine evolution
New Paleocene skeletons and the relationship of plesiadapiforms to crown-clade primates
Anthropoid Origins
Adaptive explanation for the origins of the anthropoidea (primates)
Locomotor diversity in prosimian primates
The 10kTrees website
The distal tibia of primates with special reference to the omomyidae
Middle Eocene primate tarsals from China
Vertical clinging and leaping revisited
Patterns of astragalar fibular facet orientation in extant and fossil primates and their evolutionary implications
Foot bones from Omo
New fossils of the oldest North American euprimate Teilhardina brandti (Omomyidae) from the paleocene–eocene thermal maximum
The nature of the primate grasping foot
Additional postcranial elements of T eilhardina belgica
Limb skeleton and locomotor adaptations of apidium phiomense , an Oligocene anthropoid from Egypt
Functional anatomy of the tarsier foot
The functional adaptations of primate molar teeth
A shrew-sized origin for primates
Hands of early primates
Astragalar morphology of Afradapis , a large adapiform primate from the earliest late Eocene of Egypt
Dental topography of platyrrhines and prosimians
Implications of postcranial evidence for the origin of euprimates
Locomotor and phylogenetic considerations in anthropoid evolution
Anthropoid origins-the foot evidence
Notharctine primates (Adapiformes) from the early to middle Eocene (Wasatchian-Bridgerian) of Wyoming
Astragalar morphology of late Eocene anthropoids from the Fayum Depression (Egypt) and the origin of catarrhine primates
Models for the origin of the anthropoid postcranium
Inferring hominoid and early hominid phylogeny using craniodental characters
Evolution of hallucial grasping in the primates
Body mass in comparative primatology
Astragalar and calcaneal morphology of the middle Eocene primate Anchomomys frontanyensis (Anchomomyini)
Nievesia sossisensis, a new anchomomyin (Adapiformes, Primates) from the early Late Eocene of the southern Pyrenees (Catalonia, Spain)
New adapiform primate of Old World affinities from the Devil's Graveyard Formation of Texas
New postcranial elements for the earliest Eocene fossil primate Teilhardina belgica
Species diversity and postcranial anatomy of eocene primates from Shanghuang, China
| Unique citing works | 17 |
|---|---|
| Citations per year | 1,55 |
| Citation span | 2015 - 2025 (11) |
| Citation velocity | recent |
| Highly cited | No |
| Citation types | Neutral: 17 |